The present invention relates to a separating device for process chambers of vacuum coating installations.
In vacuum coating installations for coating elongate, flat substrates such as flat glass panes by way of example, for the purpose of producing a layer arrangement composed of several layers of different coating materials one after the other, the substrate is moved through several process chambers disposed one after the other. In each of these process chambers, the substrate is coated with a coating material, for example, by sputtering, thermal evaporation or other coating processes, or the substrate is exposed to an etching process, for example, by sputtering or ion beam etching. Such processes mostly take place at a pressure that is clearly lower (low pressure, vacuum) than the atmospheric pressure, it being also possible to introduce process gases (inert or reactive) into the respective process chamber depending on the coating material. A transporting device, which extends through the entire arrangement, is mostly provided for transporting the substrate through the vacuum coating installation. This transporting device can consist, for example, of a plurality of rollers, which are disposed transversely to the transporting direction of the substrate and on which the substrate is placed. The uppermost surface line of these rollers thus defines the transporting plane and at least one of these rollers can be driven.
Lock chambers are each usually disposed at the start and end of the arrangement of process chambers, which lock chambers serve for the controlled feeding and discharge of the substrates during operation. In some vacuum coating installations, pump chambers are further provided between every two process chambers, which pump chambers serve for separating the process atmospheres of adjacent process chambers. For producing and maintaining the process pressure, vacuum pumps can be provided in the lock chambers, in one or more process chambers and in the pump chambers, if these exist.
The separation of different process atmospheres of adjacent process chambers is of fundamental importance to the quality of the coating processes since a gas exchange between process chambers having different process atmospheres can result in contaminated layers or the formation of undesirable combinations of the coating material with components of the process gas that precipitate on the substrate.